Impact sand molding machine

ABSTRACT

The present disclosure is directed to a machine for making green sand molds by an impact mechanism which imparts an impact from an impact head driven by the explosive force of suddenly released compressed air in such a way that the molding head strikes the sand and imparts its kinetic energy by way of an impulse to the sand, thereby packing the sand around the patterns. It has been discovered that by using the impulse principle in molding, the sand is uniformly packed and uniform mold hardness results.

United States Patent [72] Inventor Russell W. Taccone Erie, Pa. [211 App]. No, 799,423 [22] Filed Feb. 14, 1969 [45] Patented Nov. 30, 1970 [73] Assignee Bangor Punta Operation, Inc.

New York, N.Y.

[54] IMPACT SAND MOLDING MACHINE 3 Claims, 7 Drawing Figs.

[52] U.S.Cl 164/173 [51] Int. Cl 1322c 15/08 [50] Field of Search 164/39, 37, 173, 171

[56] References Cited UNITED STATES PATENTS 3,386,493 6/1968 .lanke etal 164/173 3,381,740 5/1968 Janke et al... 164/173 3,233,291 2/1966 Miller et a1. 164/37 3,111,730 11/1963 lvarsson 164/184 Primary Examiner-J. Spencer Overholser Assistant Examiner-V. K. Rising Attorney-Patrick J. Walsh ABSTRACT: The present disclosure is directed to a machine for making green sand molds by an impact mechanism which imparts an impact from an impact head driven by the explosive force of suddenly released compressed air in such a way that the molding head strikes the sand and imparts its kinetic energy by way of an impulse to the sand, thereby packing the sand around the patterns It has been discovered that by using the impulse principle in molding, the sand is uniformly packed and uniform mold hardness results PATENTEnunv 30 I97! SHEET 1 BF 2 HJVIL/JTUR.

1 IMPACT SAND MOLDING MACHINE PRIOR ART The impact principle has been used successfully in highenergy forging machines and in deep-draw machines, but it has never been used successfully in the part of green sand molding.

STATEMENT OF INVENTION This invention relates to green sand molding and more particularly to making green sand molds impacting a molding head on a body of loose molding sand.

BACKGROUND OF INVENTION Through the centuries that man has been ramming sand, or other substances, into boxes and calling them molds, he has sought means for making them better, faster, and cheaper.

Today, there are many machines of various manufacture on the market used daily in the production of thousands and thousands of duplicate green sand molds.

One of the best, developed several the mold. The expanding air is like an almost instantaneous explosion. This high-velocity impact action produces molds that have excellent permeability.

However, there are some serious drawbacks and disadvantages to diaphragm molding: soft edges, inability to squeeze effectively around bars, limited mold depth and, of course, wear and tear on the diaphragm itself.

Efforts to surmount these difficulties resulted in various mechanical and hydraulic combinations, such as the hydraulic squeeze machine, the hydraulic shockless"jolters.

Also, many arrangements of squeeze heads, platens and peen blocks have been developed, and used in many combinations, but high-velocity impact has been neglected in favor of slow moving high pressure for pressure s sake.

These approaches to the problem of making the perfect mold have raised a whole new set of difiiculties and disadvantages. .lolting by itself is impractical as the resulting mold lacks uniformity of hardness. Jolting takes much power and time, requires a heavy duty foundation and is rough on flasks and pattern equipment causing a scouring action on the patterns. It is one of the major sources of noise in foundries.

The usual solution is a combination of jolt and squeeze having most of the disadvantages of both.

Another approach meeting with indifferent success is the high pressure hydraulic squeeze. Hydraulic units are often complicated and expensive and are subject not only to a bad Pressure applied to molding sand is transmitted most in the direction of the applied force, except in the initial moment of contact when the flowability of the sand is at its absolute maximum and transmits the most pressure in all directions. In this instant the sand must flow with the pressure, resulting in almost perfect uniformity of density and hardness. If the pressure applied is very small the internal friction of the sand grains on each other and the forces of inertia will quickly dissipate it. However, if the force is great enough, the pressure is transmitted to all extremities equal amounts.

Working on this premise, applicant has developed Hi-Impact" molding. It consists of two large diameter pistons connected by a center ram to a compensating head which is all supported above the flask which has already been filled with sand. Compressed air accelerates this assembly downward to the point of impact with the sand.

Forty to 60 psi air pressure is sufficient to operate the Hi- Impact machine; by regulating the air pressure to the hardness of the mold can be better varied. The control of the unit is as simple as the machine itself using either two three-way valves or one four-way valve. Impacting the mold requires less than l.5 seconds. The compensating head and the sand in the flask absorb the energy of the downstroke, and on the upstroke two 2%X4 inch deceleration cushions absorb the energy.

This high-production unit is adaptable to all types of pattern equipment, and standard flasks of any reasonable depth can be used with bars in almost any arrangement. No special foundation is required, the machine can be installed on floor level, above ground, or supported on I-beams above a conveyor pit.

The molding machine has many technical advantages: Some of these are as follows:

I. Convenient and economical repetitive operation 2. Automatic cycling with relatively simple controls 3.Reduces maintenance problems associated with more complicated automatic molding machines 4. No elaborate foundation necessary 5. Low air pressure required (40-60 p.s.i.)

6. Fast circling 1-2 seconds) 7. Uniform density on all surfaces.

This versatile machine has successfully overcome most obstacles to high production-high pressure molding.

OBJECTS OF THE INVENTION It is an object of the invention to provide an improved green sand molding machine.

Another object of the invention is to provide an impact machine for forming green sand molds.

Another object of the invention is to provide an impact-type molding machine in combination with a double-acting piston arrangement for operating the molding head to provide the impact.

DESCRIPTION OF THE DRAWINGS FIG. I is a longitudinal cross-sectional view of the molding machine according to the invention.

FIG. 2 is a view similar to FIG. 1 showing the flask-carrying car moved out from the under the molding head into a filling position.

FIG. 3 is a view similar to FIG. 2 of another embodiment of the machine.

FIG. 4 is a view similar the machine.

FIG. 5 is a longitudinal cross-sectional view of another embodiment of the molding head.

FIG. 6 is a partial view of a flask supported over a molding car in stripped position.

FIG. 7 is a view ofa part of the machine shown in FIG. 3.

DETAILED DESCRIPTION OF THE DRAWINGS Now with more particular reference to the drawings, the machine as shown in FIGS. 1 and 2, has a base 10, which supports a track 11. A car 12 is supported on the track, and it rolls from a position under the head 16 to a position under the hopper 49 on wheels 24. The cushion 31 is supported at one end of the track, and cushion 32 is at the other end, so that the car will be decelerated to a stop when it comes into engagement with the cushions.

The flask I3 is supported on the car, and it may be filled with sand 14 from hopper 49 in the conventional manner. The

to FIG. 1 of another embodiment of the cushion 32. The flask is supported on pattern plate 15 that has the patterns shown.

The compensating head 16 has feet or shoes 17 supported in small cylinders 18 attached to the head. The head 16 is in turn attached to the center ram, which is fixed to the recocking piston and to the ram piston 22. These pistons are fixed together and move as a unit, and the recocking piston 20 slides in recocking cylinder 19, while the ram piston 22 slides in ram cylinder 23. The cylinder head 28 is clamped between cylinder 19 and cylinder 23.

An air supply is connected to inlet 36, and this air is directed by the valve arrangement shown through valves 29 and 30, as the case may be, to the respective cylinders and pistons.

The cylinder head is connected to the air line 29, and the cylinder head 52 is connected to the air line 30.

A source of air at a pressure between 40 to 60 p.s.i. is available at air line 55. The flow of air is controlled by a valve 38 having an actuating handle 39. By moving handle 39 the pressurized air available in line 55 can be directed as desired to line 41 in which case the ram impacts the sand or to line 40 in which case the ram is raised above the surface of the sand.

The valve spools 37 and 54 are shown in position to drive head 16 downward to form a mold in flask 15. When it is desired to form a mold in the flask 13, the handle 39 is moved to connect air from source 55 to the line 41. This will shift the valve spool 37 to the position shown to connect the air supply line 36 to the line 29, and thence to the space 26 above the ram piston 22. Air will flow from this space 26 through the port 56 to the space 57 above the recocking piston. This force on top of the recocking piston 20 will act in series with the force on piston 22 and will aid in driving the head 16 downward to impact on the sand in the flask.

At the same time, valve spool 54 will be in the position shown in FIG. 1. Air from the inlet 36 will be shut off by spool 54 and pipe will be connected through the valve spool 54 to the outlet so that there is no pressure in space 58 below the recocking piston 20.

Moving the handle 39 actuate the valve 38 to connect the air pressure from air line 55 to air line which will cause the air to be connected to the space and space 43. This will shift the valve spools 37 and 54 from the position shown so that the air in space 26 and 57 is exhausted through lines 29 and 35 and air from line 36 will be admitted through line 30 to the space 58 shown below piston 20, thus, raising the head 16 to the position shown in FIG. 2. This will lift the ram to the position shown in FIG. 2. The upward movement of ram 16 will be checked by hydraulic cushion 51. Flask 15 can then be moved on car 12 to the position shown in 2 to be refilled with sand. The completed mold can be stripped from the pattern by cylinder 70 as shown in FIG. 6.

In the embodiment of the invention shown in FIGS. 3 and 4, the machine is supported on a base 110, and the molding car 112 is supported by means of wheels I24 on the tracks shown. The car moves from one side from a position under the ram head I16 to a position under loading hopper 144 and into engagement with the cushions I31 and 132, which bring the car to a smooth stop.

The molding head 116 is supported on the ram 153, which is in turn supported on the recocking piston 120.

An air supply will be connected by a suitable valving arrangement similar to that shown in Fig. l to the pipes 129 and pipes 130. The upward movement of the ram will be cushioned by cushioning members 151, which are similar to cushioning members SI in the embodiment of the invention shown in FIG. I. The car will be moved from side to side by means of the car cylinder 33, which has a piston 133, which has piston rods shown which are similar to the car moving rods 33 in the embodiment of FIG. 1.

In the embodiment of the invention shown in FIGS. 3 and 4, the head may be held up in cocked position by means of a brake mechanism, which is in the form of an inflatable collar and is supplied air from line 162 to cause the collar to grip the shaft [M and thereby hold the head up in position.

In the embodiment of the invention shown in Fig. 7, the shaft 162 has a groove 163, which will receive the detents 164 on the other ends of the piston rods of pistons I65. Thus, air

may be inserted into the space 166 above the pistons and hold them in the groove 163 to clamp the rods [63 and hold them in an upward position.

FIG. 5 shows an embodiment of a ram having a flat plate 262, which engages the sand. This ram is driven up an down by air in space 126.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

I. A molding machine comprising a base to support a flask adapted to contain sand,

a pattern plate on said flask,

a molding head having a compensating head attached thereto adapted to be disposed in spaced relation to said sand,

said compensating head having a plurality of sand engaging feet fixed thereto whereby the force of said impact of said head on said sand is distributed uniformly throughout said sand,

a cylinder,

a molding piston and a recocking piston mounted on a common piston rod and being slidably supported in said cylinder and connected to said molding head to drive said molding head into engagement with said sand whereby an impact results on said sand sufficient to pack said sand around said pattern to form a sand mold,

a first cylinder head between said pistons defining a first space in said cylinder above said recocking piston and a second cylinder head defining a second space above said molding piston,

means to connect said first space to said second space whereby said piston rod is driven downward by air pressure on both said molding molding piston and on said recocking piston,

a compressed air source valve means connected to said cylinder above said molding piston and above said recocking piston driving said head into engagement with said sand,

valve means for exhausting air from above said molding piston and above said recocking piston and admitting air below said recocking piston to move said head to recocked position,

an opening in said second cylinder head through which said piston rod extends, and

brake means disposed on said machine adapted to engage said piston rod extension to hold said piston rod in recocked position.

2. A molding machine comprising a base to support a flask adapted to contain sand,

a pattern plate on said flask,

a molding head having a compensating head attached thereto adapted to be disposed in spaced relation to said sand,

said compensating head having a plurality of sand engaging feet fixed thereto whereby the force of said impact of said head on said sand is distributed throughout said sand,

a support frame having a cylinder mounted thereon,

a molding piston and recocking piston mounted on a common piston rod and being slidably supported in said cylinder and connected to said molding head to drive said feet into engagement with said sand whereby an impact results on said sand sufficient to pack said sand around said pattern to form a sand mold,

a first cylinder head between said pistons defining a first space in said cylinder above said recocking piston and a second cylinder head defining a second space above said molding piston,

means to connect to said first space to said second space whereby said piston rod is driven downward by air pressure on both said molding piston and on said recocking piston,

3. The machine recited in claim I wherein said flask is supported on a car,

and said car is disposed on a track, a sand hopper spaced from said molding head, means to move said car from a position under said molding head to a position under a sand hopper.

@3 3 UNITED STATES PATENT OFFiCE CERTIFICATE OF CORRECTION Patent No. 3,623,539 Dated November 30, 1971 Inventofls) Russell W. Taccone It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Front page of the patent change date patented "Nov. 30 1970" to Nov. 30 1971 front page of the patent change assignee "Bangor Punta Operation Inc. to Bangor Punta Operations Inc.--;

column 1, line 5, of the patent change "deep-draw" to deep draw column 1, line 6 of the patent change "part" to art column 1, line 12 of the patent after "molds" insert by column 2 line +7, of the patent, after "from" delete the column 3, line &6 of the patent after "shown in" insert Fig.

column 4 line 5, of the patent change "an" to and column l line 3h, of the patent after "said molding" delete molding column 4 line 52 of the patent after "a flask" insert column l line "(2 of the patent after "connect" delete to Signed and sealed this 5th day of September 1972.

(SEAL) L Attest: J

EDWARD M .FIETCHER, JR. ROBERT GOT'ISCHALK Atte sting Officer Commissioner of Patents 

1. A molding machine comprising a base to support a flask adapted to contain sand, a flask, a pattern plate on said flask, a molding head having a compensating head attached thereto adapted to be disposed in spaced relation to said sand, said compensating head having a plurality of sand engaging feet fixed thereto whereby the force of said impact of said head on said sand is distributed uniformly throughout said sand, a cylinder, a molding piston and a recocking piston mounted on a common piston rod and being slidably supported in said cylinder and connected to said molding head to drive said molding head into engagement with said sand whereby an impact results on said sand sufficient to pack said sand around said pattern to form a sand mold, a first cylinder head between said pistons defining a first space in said cylinder above said recocking piston and a second cylinder head defining a second space above said molding piston, means to connect said first space to said second space whereby said piston rod is driven downward by air pressure on both said molding molding piston and on said recocking piston, a compressed air source valve means connected to said cylinder above said molding piston and above said recocking piston driving said head into engagement with said sand, valve means for exhausting air from above said molding piston and above said recocking piston and admitting air below said recocking piston to move said head to recocked position, an opening in said second cylinder head through which said piston rod extends, and brake means disposed on said machine adapted to engage said piston rod extension to hold said piston rod in recocked position.
 2. A molding machine comprising a base to support a flask adapted to contain sand, a flask a pattern plate on said flask, a molding head having a compensating head attached thereto adapted to be disposed in spaced relation to said sand, said compensating head having a plurality of sand engaging feet fixed thereto whereby the force of said impact of said head on said sand is distributed throughout said sand, a support frame having a cylinder mounted thereon, a molding piston and recocking piston mounted on a common piston rod and being slidably supported in said cylinder and connected to said molding head to drive said feet into engagement with said sand whereby an impact results on said sand sufficient to pack said sand around said pattern to form a sand mold, a first cylinder head between said pistons defining a first space in said cylinder above said recocking piston and a second cylinder head defining a second space above said molding piston, means to connect to said first space to said second space whereby said piston rod is driven downward by air pressure on both said molding piston and on said recockiNg piston, a compressed air source valve means connected to said cylinder above said molding piston and above said recocking piston driving said head into engagement with said sand, and valve means for exhausting air from above said molding piston and above said recocking piston and admitted air below said recocking piston to move said head to recocked position.
 3. The machine recited in claim 1 wherein said flask is supported on a car, and said car is disposed on a track, a sand hopper spaced from said molding head, means to move said car from a position under said molding head to a position under a sand hopper. 